Table 2: Burning questions on vitamin D prescription in CKD-MBD.

VDRANutritional vitamin DVDRA or calcimimetic

(i) Are VDRA superior to placebo in terms of cardiovascular events and survival?
(ii) Do vitamin D analogs provide a better achievement of patient centered outcomes compared to calcitriol?
(iii) Is any VDRA superior to the others in achieving KDIGO targets and improving albuminuria, LVH, VC, bone health, hospitalizations, and survival?
(iv) Will paricalcitol ameliorate CKD progression and cardiovascular events through the benefits on albuminuria and LVH?
(v) Should VDRA be suspended in those patients reaching PTH levels ≤ 150 pg/mL?
(i) Which are the optimal thresholds independently linked to SHPT and survival?
(ii) Which is the best nutritional vitamin D regimen in terms of type and doses to replenish deficiency and treat SHPT?
(iii) Will the replenishment be a cost-effective prevention against SHPT and CKD-MBD?
(iv) Will the replenishment improve CKD progression, diabetes, infections, and survival?
(v) Will the coadministration of native and active vitamin D be additive against CKD-MBD, infections, diabetes, and mortality?
(i) Is a VDRA-centered superior to a calcimimetic-centered therapy to control SHPT and survival?
(ii) Which is the best cost-effective strategy in CKD-MBD: VDRA alone, calcimimetic alone, or a balanced association of VDRA and calcimimetic?

CKD: chronic kidney disease; SHPT: secondary hyperparathyroidism; LVH: left ventricular hypertrophy; VC: vascular calcification; VDRA: vitamin D receptor activators.